The present invention relates to a setpoint generator, in particular for a brake pedal in an automotive vehicle for the control of an electrically controlled brake system, with at least two parallely connected sensors working in accordance with different principles, with subsequently connected electronic input circuits.
Such a setpoint generator, in particular for a brake pedal in an automotive vehicle, is known from published German patent application 35 04 096. It is for the control of an electric brake system and contains a parallel connection of a travel sensor and a force sensor, the force sensor supplying the reference variable. To the sensors, there are subsequently connected electronic main circuits which verify the sensor signals according to diverse criteria with respect to plausibility, and which, in case of an error, trigger a warning light. In order to provide a maximum extent of safety and accuracy, the sensors of the known setpoint generator proceed on different principles, and only in case of a stated malfunction of the force sensor, the reference variable is supplied by the travel sensor.
It is to be regarded as a disadvantage of the known setpoint generator that, in particular for exceptionally small signals, the random noise is in the order of magnitude of the signals and thereby distorts them. Hence, there is provided a filtration of the signals which, however, results in a bad temporal behavior, i.e. a slow reaction. This conveys an inert vehicle behavior to the driver which is undesirable. If, however, no filtration is carried out, an uneven braking behavior will occur, which, as well, is felt to be disturbing.
An object of the invention therefore is to prevent the disadvantages of the known setpoint generator and thus to enhance the comfort.